CS Colloquium

Date: 17.12.2025

Time: 14:00-15:00

Speaker: Mahmood Sharif, Tel Aviv University

Title: From Attacks to Security-Enhancing Insights in NLP Models

Abstract:
Recent advances in natural language processing (NLP) have given rise to powerful and transformative models, including large language models (LLMs) and text retrievers. Still, critical concerns remain regarding the security of these models: chiefly, LLMs can be jailbroken and misused for malicious purposes (e.g., launching cyberattacks), and text retrievers in search applications can be manipulated to retrieve adversary-chosen content. In this talk, I will present our recent efforts toward making LLMs and text retrievers more secure. In particular, I will show how potent attacks can provide explanations for models' susceptibility, which, in turn, enable us to enhance models' security. Crucially, I will also demonstrate how our insights can inform the design of even stronger attacks, effectively forming a cycle that guides continuous model improvements.

Based on joint work with Matan Ben-Tov and Mor Geva.

Bio:

Mahmood Sharif is a senior lecturer at the Blavatnik School of Computer Science at Tel Aviv University, where he directs the privacy, learning, usability, and security (PLUS) group---a research group primarily working at the intersections of computer security and privacy with machine learning, specifically adversarial machine learning, and with human factors. Mahmood obtained his Ph.D. from Carnegie Mellon University, where he was affiliated with the CyLab Security and Privacy Institute. Before joining Tel Aviv University, Mahmood was a postdoctoral researcher in the VMware Research Group and a principal research engineer in the NortonLifeLock Research Group. His work has been recognized by multiple awards, including an Intel Rising Star Faculty award and a Maof prize for outstanding new faculty.